GB2253074A

GB2253074A - Washing machine

Info

Publication number: GB2253074A
Application number: GB9202998A
Authority: GB
Inventors: Tetsukazu Tanaka
Original assignee: Toshiba Corp
Current assignee: Toshiba Corp
Priority date: 1991-02-20
Filing date: 1992-02-13
Publication date: 1992-08-26
Anticipated expiration: 2012-02-13
Also published as: TW207556B; KR920016642A; KR960012121B1; JP2991515B2; JPH04266796A; GB9202998D0; GB2253074B

Abstract

A washing machine includes an outer tub (2), an inner tub (8) rotatably mounted in the outer tub (2), a drive motor for driving an agitator (9) provided in the inner tub (8), a switch input section including manually operated switches for producing switch signals, and a control device (11) incorporating a storage for storing an operational program for rotating the drive motor in forward and reverse directions alternately in a wash step. The number of revolutions of the 2 drive motor in a unit period of time is varied among a plurality of different values, the control device (11) being responsive to the switch signals from the switch input section for controlling the drive motor in the wash step so that the drive motor is driven in accordance with the operational program. Jeans and lingerie washing programmes are <IMAGE>

Description

WASHING MACHINE This invention relates to a washing machine having an agitator driven by an electric motor forward and reverse rotated so that washing is performed, and more particularly to a control for such a motor of the washing machine.

Conventionally, an electric drive motor employed in washing machines is forward and reverse rotated alternately for driving an agitation so that it is rotated forward and reverse, thereby producing water streams. Such a rotation of the drive motor produces only regular water streams at every washing operation. The produced water streams are thus monotonous and accordingly, a desirable washing effect cannot be achieved.

It may be considered that when the drive motor is rotated at a high speed for a long period of time, intensive water streams are produced even though the water streams are regular. In this case, however, the clothes to be washed are intertwined with one another during the washing operation, which reduces smoothness in movement of the clothes during the washing operation. Consequently, a desirable washing effect cannot be achieved in this case too.

It may be further considered that the drive motor is rotated at a low speed for a relatively short period of time so that the intertwining of the clothes is reduced. In this case only weak water streams can be caused while the intertwining of the clothes can be reduced. Consequently, a desirable washing effect cannot be achieved either.

Therefore, an object of the present invention is to provide a washing machine wherein the drive motor is controlled in the wash step so that complex water streams can be produced and a sufficient washing effect can be achieved.

In an aspect, the present invention provides a washing machine comprising an outer tub, an inner tub rotatably mounted in the outer tub, a drive motor for driving an agitator provided in the inner tub, a switch input section including switches manually operated and producing switch signals, and control means incorporating storage means for storing an operational program for rotating the drive motor in forward and reverse directions alternately in a wash step so that the number of revolution of the drive motor in a unit period of time is varied in a plurality of different values, the control means being responsive to the switch signals from the switch input section, for controlling the drive motor in the wash step so that the drive motor is driven in accordance with the operational program.

The intensity of the water stream produced by the agitator is varied in a plurality of modes when the drive motor is rotated in the forward and reverse directions alternately in the wash step so that the number of revolution of the drive motor in the unit period of time is varied in the plurality of different values. Consequently, the clothes can be restrained from being tangled or intertwined and the movement of the clothes during the wash step can be smoothed, resulting in an effective washing.

In the above-described washing machine, the storage means incorporated in the control means may further store another operational program for rotating the drive motor in the forward and reverse directions alternately in the wash step so that a period of time of energization of the drive motor is varied in a plurality of values. Consequently, the intensity of the water stream produced by the agitator can be varied in a further complicate manner.

The number of values of revolution of the drive motor in the unit period of time and the number of periods of energization of the drive motor may differ depending upon washing courses set in accordance with the kinds, volume or degree of soil of the clothes to be washed. Consequently, the washing operation can be performed in a suitable motor drive mode in each washing course.

The storage means incorporated in the control means may store an operational program for rotating the drive motor in the forward and reverse directions in the wash step in a reiterative combination pattern that each of the number of revolution of the drive motor in the unit period and the period of time of energization of the drive motor is varied in a plurality of values. Consequently, an effective washing operation can be performed in an easy control manner.

The number of values of revolution of the drive motor in the unit period of time may differ depending upon, particularly, washing courses set in accordance with the kinds of clothes to be washed. The washing operation can be thus performed in accordance with the kinds of clothes to be washed.

The invention will be described, merely by way of example, with reference to the accompanying drawings in which: FIG. 1 is a flowchart for explaining the operation of the washing machine in accordance with an embodiment of the invention; FIG. 2 is a longitudinal sectional view of the washing machine; FIG. 3 is a block diagram showing an electrical arrangement of the washing machine; FIG. 4 is a time chart for explaining a first drive mode; FIGS. Sa to 5e schematically illustrate changes in the water stream in the first drive mode; FIG. 6 is a time chart for explaining a second drive mode; FIGS. 7a to 7c schematically illustrate changes in the water stream in the second drive mode; FIG. 8 is a time chart for explaining a third drive mode; and FIG. 9 schematically illustrates a water stream mode in the third drive mode.

One embodiment of the present invention will be described with reference to the accompanying drawings.

Referring first to FIG. 2, the washing machine comprises an outer cabinet 1 enclosing an outer tub 2. A drive mechanism 3 is provided below the outer tub 2. The drive mechanism 3 includes an electric motor 4 driven for washing and dehydrating operations, and particularly a dc brushless motor. A drain valve 5 is also provided below the outer tub 2 and a drain hose 6 is coupled with the drain valve 5. An inner tub 8 is mounted in the outer tub 2. The inner tub 8 has number of dehydrating apertures 7 formed in its peripheral wall and driven by the drive mechanism 7 in a dehydration step. An agitator 9 is rotatively mounted in the inner tub 8. The agitator 9 is driven by the drive mechanism in wash and rinse steps.

A top cover 10 is attached to the top of the outer cabinet 1. A first microcomputer-based control device 11 as control means is provided in the front inside of the top cover 10. A water supply valve 12 is provided in the rear inside of the top cover 10 for supplying water to the inner tub 8 (outer tub 2). A water level sensor 13 is also mounted in the rear inside of the top cover 10 for sensing the water level in the outer tub 2 (inner tub 8). A control box 14 is mounted on the rear walls of the outer casing 1 and the top cover 10. A second microcomputer-based control device 15 as control means is provided in the control box 14.

Referring to FIG. 3, switch signals from a switch input section 16 comprising various switches such as a start switch, a course selecting switch, a period setting switch or the like (none of them being shown) are supplied to the first control device 11. A water level signal from the water level sensor 13 is also supplied to the first control device 11. Based on these input signals and a control program previously stored in storage means 11a incorporated in the first control device 11, the first control device 11 supplies a control signal to a display drive circuit 17 for controlling a display 18. The control device 11 further supplies a control signal to a valve drive circuit 19 for controlling the water supply valve 12 and the drain valve 15. Additionally, the first control device 11 supplies a command signal to the second control device 15 for running the drive motor 4. Based on the command signal from the first control device, the second control device 15 supplies control signals to a motor drive circuit 20 for controlling drive, stop, forward and reverse rotation and number of revolution. The motor drive circuit 20 comprises an inverter circuit effectuating the above-described control.

The first control device 11 further supplies the second control device 15 with a data transfer start signal, clock signals and a data transfer completion signal. The second control device 15 supplies a data reception signal to the first control device 11.

The operation of the washing machine will now be described with reference to FIG. 1. Upon start of operation, the first control device 11 receives set inputs from the switch input section 16 at step S1. The first control device 11 then determines whether the start switch (not shown) has been operated or not at step S2. When determining that the start switch has been operated, the first control device 11 further determines whether a washing course selected by manual operation of the course selecting switch (not shown) is a jeans washing course or not at step S3. When it is determined that the set washing course is the jeans washing course, the control device 11 reads out the control program for the jeans washing course from the storage means 11a. The water supply valve 12 is then opened at step S4 so that water is supplied to the inner tub 8 (outer tub 2) at step S5.Subsequently, the first control device 11 controls the second control device 15 so that the drive motor 4 is driven in a first drive mode for execution of washing, thereby rotating the agitator 9 at step S5. In the first drive mode, the drive motor 4 is rotated in forward and reverse directions alternately at 110 r.p.m. in a pattern of three second energization and one second deenergization for causing intensive whirlpool streams (PATTERN 1). The drive motor 4 is then rotated in the forward and reverse directions alternately at 120 r.p.m. in a pattern of 1.5 second energization and 0.5 second deenergization for causing medium water streams (PATTERN 2). The motor drive 4 is further rotated in the forward and reverse directions at 115 r.p.m. in a pattern of 1.4 second energization and 0.6 second energization for causing standard water streams (PATTERN 3).Then, the drive motor 4 is rotated in the forward and reverse directions alternately at 80 r.p.m. in a pattern of one second energization and one second deenergization for causing the medium water streams (PATTERN 4). At last, the drive motor 4 is rotated in the forward and reverse directions alternately at 65 r.p.m. in a pattern of 0.5 second energization and 0.5 second deenergization for causing weak water streams (PATTERN 5).

These energization and deenergization patterns are repeated.

FIG. 4 illustrates a manner of energizing and deenergizing the drive motor 4 in the first drive mode and FIGS. Sa-Se illustrate changing water streams in the inner tub 8. In this case FIGS. 5a through 5e correspond to the abovedescribed PATTERNS 1 through 5 respectively.

When determining at step S3 that the selected washing course is not the jeans washing course, the first control device 11 determines whether the washing course selected by manual operation of the course selecting switch is a lingerie washing course or not, at step S6. When it is determined that the selected washing course is the lingerie washing course, the first control device 11 reads out a control program for the lingerie washing course from the storage means 11a. Then, the water supply to the inner tub 8 is performed at step S7 in the same manner as in step S4. Subsequently, the first control device 11 controls the second control device 15 so that the drive motor 4 is driven in a second drive mode for execution of washing, at step S8.

In the second drive mode, the drive motor 4 is rotated in the forward and reverse directions alternately at 110 r.p.m.

in a pattern of 1.2 second energization and 0.8 second deenergization for causing the standard water streams (PATTERN 1). The drive motor 4 is then rotated in the forward and reverse directions alternately at 80 r.p.m. in a pattern of one second energization and one second deenergization for causing the medium water streams (PATTERN 2). The drive motor 4 is further rotated in the forward and reverse directions alternately at 60 r.p.m. in a pattern of 0.5 second energization and 0.5 second energization for causing the weak water streams ( PATTERN 3). These energization and deenergization patterns are repeated.

FIG. 6 illustrates a manner of energizing and deenergizing the drive motor 4 in the second drive mode and FIGS. 7a-7c illustrate changing water streams in the inner tub 8. In this case FIGS. 7a through 7c correspond to the abovedescribed PATTERNS 1 through 3 respectively.

When determining at step S6 that the selected washing course is not the lingerie washing course, the first control device 11 determines that the selected washing course is a standard washing course. The water supply to the inner tub 8 is performed at step S9 in the same manner as in step S4.

Subsequently, the first control device 11 controls the second control device 15 so that the drive motor 4 is rotated in the forward and reverse directions alternately in a pattern of 1.5 second energization and 0.6 second deenergization repeatedly, at step S10. FIG. 8 illustrates a manner of energizing and deenergizing the motor 4 and FIG. 9 illustrates the water stream caused in the inner tub 8 in the above-described rotation pattern of the drive motor 4.

In accordance with the above-described control manners, the drive motor 4 is rotated in the forward and reverse directions alternately at the number of revolution per unit period of time varied in a plurality of values in the jeans and lingerie washing courses. Accordingly, since the intensity of the water stream is varied in a plurality of modes, the clothes are prevented from being intertwined during washing and the smoothness in the movement of the clothes is enhanced in contrast with the prior art in which the water stream is regular and monotonous. Consequently, a sufficient washing effect can be achieved from the washing.

Furthermore, the period of energization of the drive motor 4 is varied in a plurality of values as well as its number of revolution per unit period of time. Consequently, since the intensity of the water stream is changed in a further complicate manner, a further sufficient washing effect can be achieved.

Furthermore, the number of values varied in the number of revolution of the motor 4 per unit period and in the period of time of energization of the drive motor 4 differ depending upon the washing courses. Consequently, the washing operation can be performed in each washing course having suitable contents of changes in the number of revolution per unit period and the period of energization of the drive motor 4.

Additionally, the drive motor 4 is rotated in the forward and reverse directions alternately in the first or second drive modes in each of which patterns of combination of a plurality of values of revolution of the drive motor 4 per unit period and its period of time of energization are repeated. Consequently, sufficient washing effect can be achieved by employment of an easy control manner.

The contents of the drive modes differ in accordance with the kinds of the clothes to be washed. Consequently, washing can be performed in each course having suitable contents of values in the number of revolution of the drive motor 4 per unit period and its period of time of energization in accordance with the kinds of the clothes to be washed.

In the foregoing embodiment, the number of revolution per unit period and the period of time of energization of the drive motor 4 are varied in a plurality of respective patterns in each of the jeans and lingerie washing courses.

However, these drive modes may also be employed for washing other kinds of clothes. For example, a plurality of washing courses may be provided in accordance with the volume of clothes to be washed or the degree of soil of the clothes to be washed.

Furthermore, each of the first and second drive modes may be determined from additional factors such as the volume and the degree of soil of the clothes to be washed. The above-described numeral values and the combination patterns in each drive mode may be changed.

The foregoing disclosure and drawings are merely illustrative of the principles of the present invention and are not to be interpreted in a limiting sense. The only limitation is to be determined from the scope of the appended claims.

Claims

WE CLAIM:

1. A washing machine comprising: a) a tub in which an agitator is mounted; b) a drive motor for driving the agitator mounted in the tub; c) a switch input section including switches manually operated and producing switch signals; and d) control means incorporating storage means for storing an operational program for rotating the drive motor in forward and reverse directions alternately in a wash step so that the number of revolution of the drive motor in a unit period of time is varied in a plurality of different values, the control means being responsive to the switch signals from the switch input section, for controlling the drive motor in the wash step so that the drive motor is driven in accordance with the operational program.

2. A washing machine according to claim 1, wherein the storage means incorporated in the control means further stores another operational program for rotating the drive motor in the forward and reverse directions alternately in the wash step so that a period of time of energization of the drive motor is varied in a plurality of values.

3. A washing machine according to claim 1, wherein the number of values of revolution of the drive motor in the unit period of time differs depending upon washing courses.

4. A washing machine according to claim 2, wherein the number of values of period of energization of the drive motor differs depending upon washing courses.

5. A washing machine according to claim 2, wherein the storage means incorporated in the control means stores an operational program for rotating the drive motor in the forward and reverse directions in the wash step in a reiterative combination pattern that each of the number of revolution of the drive motor in the unit period and the period of time of energization of the drive motor is varied in a plurality of values.

6. A washing machine according to claim 3, wherein the washing courses are determined based on kinds of clothes to be washed.

7. A washing machine according to claim 4, wherein the washing courses are determined based on kinds of clothes to be washed.

8. A washing machine substantially as described herein with reference to the accompanying drawings.